Function createAggregator

lodash.js:4911–4918

* Creates a function like `_.groupBy`. * * @private * @param {Function} setter The function to set accumulator values. * @param {Function} [initializer] The accumulator object initializer. * @returns {Function} Returns the new aggregator function.

(setter, initializer)

     * @returns {Function} Returns the new aggregator function.
     */
    function createAggregator(setter, initializer) {
      return function(collection, iteratee) {
        var func = isArray(collection) ? arrayAggregator : baseAggregator,
            accumulator = initializer ? initializer() : {};

        return func(collection, setter, getIteratee(iteratee, 2), accumulator);
      };
    }

    /**
     * Creates a function like `_.assign`.